Interlocking control apparatus



June 24, 1941.

L. E. SPRAY INTERLOCKING CONTROL APPARATUS 9 Sheets-Sheet 1 Filed May22, 1934 INVENTOR BY ELY Drag,

CZJK'Z/IMOL HIS A TTORNEY June 24,? 1941.

Filed May 22, 1934 9 Sheets-Sheet 2 ag mfiw fivk v r F mm Q ow 7 EN SN mQMN MAN NQENQMNNRQNN ENNQN EN EN MN HIS ATTORNEY INVENTOR E Spray.

k Lam L. E. SPRAY INTERLOCKING CONTROL APPARATUS June 24, 1941..

Fiiled May 22-, 1934 9 Sheets-Sheet s INVENTOR L yzpfiE. 'or'ag.

BY Q Q HIS A TTORNEY V/IWQ June 24, 1941-." 1.. E, SPRAY INTERLOCKINGCONTROL APPARATUS 9 Sheets-Sheet 4 Filed May 22, 1934 INVENTOR Lewze E.'prag, BY

HIS ATTORNEY Q NW @EQQ M N W NW @QQNQ V N E ww mw w NN NQN WW June 24,1941. PR Y INTERLOCKING CONTROL APPARATUS Filed May 22, 1934 9Sheets-Sheet 5 INVENTOR Lamer E. Spfiag BY Qipkz/xuze,

HIS ATTORNEY June 24, 1941. L. E. SPRAY INTERLOCKING CONTROL APPARATUSFiled May 22, 1934 9 Sheets-Sheet 6 June 24, 1941. L. E. SPRAYINTERLOCKING CONTROL APPARATUS 9 Sheets-Sheet '7 Filed May 22, 1934 mmEfA P 9 Sheets-Sheet 8 L. E. SPRAY Filed May 22, 1934 INTERLOGKINGCONTROL APPARATUS June 24, 19411.

R NN INVENTOR 'pfiag.

BY Q/R XLWJ/ Lemafl E.

was' ATTORNEY June 24; 1941..

L. E. SPRAY INTERLOCKING CONTROL APPARATUS Fi led May 22, 1954 9Sheets-Sheet 9 R Y m@ m m m V 1 H W A M 5 w m 9 L Patented June 24, 1941UNITED STTS ()FFICE Union Switch & Signal Company,

Swissvale,

Pa., a corporation of Pennsylvania Application May 22, 1934, Serial No.726,957

80 Claims. (Cl. 246-134 My invention relates to interlocking controlapparatus, and is particularly adapted for, though not limited to, thecontrol of railway track switches and signals in a railway switching orinterlocking layout.

One feature of my invention is the provision of novel and improvedinterlocking control apparatus Without the use of interlocked levers.Another feature of my invention is the provision of novel and improvedindication apparatus associated with such interlocking controlapparatus.

More particularly, the principal object of my invention is the provisionof a system of route interlocking which is an improvement upon thesystems disclosed in my copending applications, Serial No. 323,286,filed December 3, 1928, and Serial No. 561,422 filed September 5, 1931,for Multiple control apparatus.

In the systems of these prior applications, I provide a control boardhaving thereon a miniature diagram of the track layout, with routebuttons for controlling the switches and signals identified by theirlocation on the track diagram at points corresponding to the signallocations. A similar control board is employed herein, in threedifferent forms. In the first form, rotary buttons which may be turnedin either direction from a normal position are used, as in the system ofmy application, Serial No. 323,286, and the routes are established. andthe corresponding signals are cleared in a similar manner, namely byoperating the two buttons for the signal locations at the opposite endsof the route, in one direction or the other according to the directionof the trafiic movement desired. One object of the present invention isthe provision in a system of this character, of an improved arrangementof interlocked route relays by means of which all the switches of aroute are controlled by the pairof buttons identifying the opposite endsof the route, but which employs a smaller number of relays than requiredheretofore. This arrangement consists of a route circuit networkcomprising a plurality of interconnected circuits which include a routecircuit for each route extending between contacts controlled by thebuttons at its opposite ends and having in series therein a route relayfor each switch of the route for operating the switch to the requiredposition.

In another form of the prosentinvention only a momentary operation ofthe button at the exit end of the representation of a route is required,and the manual cancellation may be etfected by merely restoring thebutton at the entranc end to normal. This is accomplished by theprovision of an exit stick relay for each route end, in' the routecircuit network.

In a third form, separate entrance and exit push buttons replace therotary buttons and an entrance stick relay is provided for each entrancebutton so that only a momentary pressing of an entrance button at oneend, and of an exit button at the opposite end of the representation ofthe desired route is required to establish that route and clear thecorresponding signal. In this form, the route is cancelled automaticallywhen a train enters the first track section of the route, or i cancelledmanually by pressing a cancelling button, as in the system of my priorapplication Serial No. 561,422.

A feature of the present invention relates to the provision of means forselecting one or another of two alternative routes between two signallocations.

A further feature of my invention relates to improvements in theindication apparatus, comprising the provision of lamps in the tracks ofthe operators track diagram for indicating the different routes whenestablished, these lamps being also employed to indicate both thepositions of the track switches and to indicate the passage of trainsover the routes.

I will describe three forms of apparatus embodying my invention, andwill then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1 to 9, inclusive, are diagrammaticviews showing the component parts of one form of apparatus embodying myinvention. A second form of apparatus embodying my invention is similarto the first form shown in Figs. 1 to 9, except that the parts of theapparatus shown in Figs. 1, 3, 6, 7 and 9 are modified as shown in Figs.1 3 6 7 and 9 respectively. A third form of apparatus embodying myinvention is also similar to the first form, but differs from it in thatthe parts shown in Figs. 2, 3, 4, 5 and 9 are modified as shown in Figs.2 3 4 5 and 9 respectively.

Similar reference characters refer to similar parts in each of theviews.

Referring first to Fig. 1, this drawing shows a stretch of double trackrailway, tracks ac and bb of which are interconnected through a,crossover ee with which they are respectively joined by switches H and Hand are likewise interconnected by a second crossover ff with which theyare respectively joined by switches H and H Tracks ac and bi) are alsorespectively joined to passing sidings cc and dd by switches H and H Thereference characters I and I designate the rails of tracks ac, and thereference characters 2 and 2 designate the rails of track b b. Theserails are divided by insulated joints 3 to form a. plurality of tracksections a-A, A-z'i, ii-jy', y'j-E, B-mm, mm-G, G-D and D-d.

Each of these track sections is Supplied with current by a battery 4connected across the rails adjacent one end of the section. A trackrelay, designated by the reference character T with a distinguishingexponent, is connected across the rails adjacent the opposite end ofeach track section.

Reference character S, with distinguishing exponents, designates signalswhich are placed adjacent the points A, B, C, D, E, and F, and which, ashere shown, are of the semaphore type. Signals S S and S are mounted ona common mast l0, and signals 5 S and S are mounted o n a common mast 9.Signals S S S, S and S govern eastbound trafiic moves, that is, moveswhich are made over the stretch of track from left to right as shown inthe drawings, and signals S, S S S and S govern westbound traffic moves,that is, moves which are made over the stretch of track'from right toleft as shown in the drawings.

Between the group of eastbound signals and the group of westboundsignals, eleven different routes may-be established according to theposition of the various switches. Over each of these routes, trafiic canproceed in either direction, that is, from west .to east, or from eastto west, as controlled by a signalfor each direction of traffic overeach route. i l

The arrangements of the switches for these various routes are as givenin the following table:

Route l,--A to E, switches H H and H normal.

Route 2,-A to F, switches H and H normal,

and H reversed.

Route 3,A to D, switches H and H reversed,

and H normal.

Route 4,A to E, switches H H H and H reversed, and H normal.

Route 5,-A to F, switches H H H H and H reversed. V

Route 6,-B to D, switches H H andlP normal:

Route 7,-B to E, switches H H and H normal, and H and H reversed.

Route 8,B to F, switches H and H normal, and

H H and H reversed.

Route 9,C to D, switch H reversed, and switches H and H normal.

Route l0,C to E, switches H I-l and H reversed, and I-I and H normal.

Route 1 1,-'-C to F, switchesH H, H and H reversed, and H normal.

E'ach track section in which a switch is located will'be referred tohereinafter as a detector section. Track section's a,A and Dd in therear of signals S a'nd S respectively, will be referred to as approachtrack sections.

Each switch H is operated by a mechanism, which may be an electric motoror any other suitable device, designated by the reference character Mwith an exponent corresponding with that of the reference character Hfor the switch. The mechanisms M and M for operating switches H 'and Hrespectively, of crossover ff are controlled in multiple bypole-changing contacts of a polarized relay m the control for which isshown in Fig. '7. The control of the mechanisms for operating switches Hand H of crossover ee is similar to that for mechanisms M and M and istherefore not shown in the drawing. Mechanism M for operating switch His controlled by pole-changing contacts of a polarized relay m Thecontrol for the mechanism of switch H is similar to that for mechanism Mand is therefore omitted from the drawings.

Operated in conjunction with each switch H is a circuit controllerdesignated by the reference character 11; with an exponent correspondingwith that of the reference character H for the switch.

The circuit controller 31 is provided with polechanging contact arms I8and I9. Polarized relay m for controlling operations of switch H is alsoprovided with polar contacts H and 26 A circuit for controlling apolarized switch indication relay b is so controlled by contacts and 20and by contact arms l8 and I9 of circuit controller 1 that the contactsof indication relay n will become closed in the normal direction whenswitch H occupies its normal position while its control relay m isenergized in the normal direction, and the contacts of indication relay71. will become closed in the reverse direction when switch H occupiesits reverse position while relay m is energized in the reversedirection. The control of relay-h by a circuit controller y andpolarized relay m is similar to that for relay I1 and is therefore notshown in the drawings.

Switch circuit controller 111 is provided with contact arms 23 and 24,and circuit controller 11 is provided with contact arms 22, 25, 26 and21. m which controls operations of switches H and. H are so associatedwith contact arms 22, 25, 2B and 21 of circuit controller 111 andcontact arms 23 and 24 of circuit controller 1/ in the control of apolarized switch indication relay h as to cause the polar contacts ofrelay h to be closed in the normal direction when switches H and I-Ioccupy their normal position while relay m is energized in the normaldirection, and to cause the polar contacts of relay 71 to be closed inthe reverse direction when switches H and H are in their reverseposition while relay m is energized in the reverse direction. The

control of a polarized switch indication relay h by switches H and H andby relay m -is similar to that of relay h by switches H and I-I and byrelay m and is therefore not shown in the drawings.

Each of the signals shown in the drawings operates a circuit controllerhaving contacts which are closed when and only when their signal isindicating stop. Such contacts are shown adjacent the signal diagrams inFig. l, and are designated by the reference numbers 29, 30, 3| and 36,respectively. Similar contacts, designated by the reference numbers 201,299, 2, 2i2, 228, 230, 232 and 233, are shown adjacent the diagrams forsignals S and S in Figs. 9, 9 and 9 Contacts 3|, 30 and 29, shown inFig. 1 adjacent the diagrams for signals S are operated by signals S Sand 8 respectively, and are included in the control circuit for anapproach locking relay designated by the reference character P Similarcontacts 3!, 30 and 29, shown adjacent the diagrams for signals S inFig. 1, are operated by signals S S and S respectively, and are includedin the control circuit for a second approach locking relay designated byContacts 21" and 28* of polarized relay the reference character PSimilar contacts 36, operated by the signals S S S and S respectively,are included in the control circuits for stick locking relays Q Q Q andQ respectively.

Approach locking relay P becomes deenergized when the arm of any of thesignals S leaves its stop position. Relay P is similarly controlled bysignals 5*. Each of these approach locking relays is also so controlledthat, while a respective approach track relay is deenergized, theapproach locking relay can again become energized only through a backcontact of the track relay for an adjacent detector track section, orthrough a time releasing device contact which will become closed onlyupon the lapse of a measured interval of time after the beginning of theoperation of the releasing device. These releasing devices may be of thewell-known clockwork type, and are designated by the reference characterJ with distinguishing exponents.

Stick locking relay Q becomes deenergized when the arm of signal Sleaves its stop position. Relay Q can then again become energized onlyupon the deenergization of detector track section relay T or upon theclosing of contact 39 of a time relay N when signal S is again indicatinstop. As here shown, time relay N is of the thermal type, comprising aheater winding 40, which, upon the lapse of a period of time after ithas become energized, causes its contact 39 to close. Relays Q Q and Qare controlled similarly to relay Q Each of the approach and sticklocking relays P and Q, when deenergized, prevents the operation of eachswitch in a route governed by a signal which controls the correspondingrelay P or Q, and enforces, at times, after a signal has been returnedto its stop position, the lapse of a measured time interval before theswitches in the route governed bythe signal can again be operated.

In each of the drawings, the contacts operated by the various relays, orby the time releases J, or by other control devices which will behereinafter described, are identified by numbers, such numbers havingdistinguishing exponents when the contacts are not shown adjacent therelay, release, or other device by which they are operated. The exponentfor each of these contact numbers comprises the reference character andexponent for the respective relay, release, or other device. Forexample, the exponent T for contact 31, shown in a pick-up circuit forrelay Q in Fig. 1, comprises the reference character T and its exponent5 for track relay T which opcrates contact 31'. Similarly, exponent mfor contact in the operating circuit for mechanism M comprises referencecharacter m and its exponent 4 for switch control relay m which operatescontact I 1 In Fig. 2, a combined track diagram and operating board isshown, on which manually operable devices, designated by the referencecharacter K with distinguishing exponents, are disposed adjacent pointsA, B, C, D, E, F, G and Adjacent points A and D, call-on control pushbuttons U and U respectively, are also shown.

As indicated by the drawings each of the devices K may be a lever havinga normal position n, a reverse position r to the right, and a reverseposition f to the left. Levers K operate contacts in the circuits ofFigs. 3, 4 and 9 of the first form of apparatus shown in the drawings,or in the 7 circuits of Figs. 3 4 and 9 of the second formof apparatusshown in the drawings.

For arranging the switches of each route in the positions required forthe route, and for clearing the eastbound signal for the route, theleverman will place the lever for each end of the route and for anintermediate point G or ii in its 1' position. Similarly, for arrangingthe switches of each route and for clearing the westbound signal for theroute, the leverman will place the lever for each end of the route andfor intermediate point G or ii in its 1 position.

Levers are required for intermediate runaround points, such for exampleas G and ii, only if it is desired to arrange for more than one traflicroute between any two of the route ends at points A, B, C, D, E and F.Levers for points G and ii provide for so-called run-around moves overcrossovers cc and 17, thus permitting trains to go from point A to pointE over route 1 with switch es H and H in their normal positions, or overroute 4 with switches H H H and I-l in their reverse positions. Trainsmay similarly go from point A to point F over either route 2 or 5.

When the levers, such for example as levers K and K for the intermediaterun-around points are not required, the contacts operated by theselovers will be replaced by direct wire connections. The contacts whichwill be so replaced are contacts lilll and 94 shown in the circuits inFig. 3, and contacts IBG and I89 shown in the circuits in Fig. 9.

On the operating board adjacent the representation of each switch H, aretwo indicators shown as electric lamps, one for each position of thecorresponding switch. Each of these indicators is designated by thereference character 6 with an exponent corresponding to the associatedposition of its switch, and is mounted in the representation of theroute in which the switch is included in the associated position. A

Fig. 3 shows a network of circuits controlled by levers K forcontrolling normal and reverse switch control relays which aredesignated by the reference characters X and R, respectively, withexponents corresponding to those for the switches which they control.When the levers K for any route are placed in either of their reversepositions, the normal or the reverse control relay for each switch inthe corresponding route is controlled in series with the normal or thereverse control relay for each other switch in the same route. Forexample, when levers K K and K are reversed, switch control relays X Xand R are energized in series.

In Fig. 4, circuits are shown controlled by push button circuitcontrollers U and U and by levers K and K for call-on control relays Zand Z for controlling signals S and S, respectively. Each of the pushbutton contacts 234 and 231 is biased in a suitable manner to thenormally open position shown in the drawings. This may be accomplishedby the use of a coiled spring, such for example as spring 280, shown inFig. 4, one end of which is attached to the movable arm of contact 234and the other end'of which is attached to a fixed portion 28! of pushbutton circuit controller U Fig. 5 shows circuits for controllingindicators e which are mounted on the operating board shown in Fig. 2.It will be noted that each of these circuits will be closed forenergizing a corresponding indicator e only if the detector tracksection for the corresponding switch is unoccupied, and only if therelays X or R for the switch 4- aceaorl isenerg zed a d i the indi a ire a h or same switch is energized in correspondence with the relay X orR which is energized.

Fig. 6 shows route locking relays which are deenergized whencorresponding signals are cleared, and which can again be energized onlyif given track sections are unoccupied.

Circuits are shown in Fig. '7 for controlling polarized switch controlrelays m. Each relay m can be energized in the normal direction only ift e corresponding relay X is energized and the corresponding relay R isdeenergized. Each relay m can be energized in a reverse direction onlyif the corresponding relay R is energized and the corresponding relay Xis deenergized.

In Fig. 8, circuits are shown for controlling signal stick relays L andL which control, in part, signals S and S respectively.

Fig. v9 shows a signal control network comprising a plurality ofinterconnected signal control circuits each of which can be closed onlyif all the control levers for a corresponding route are in a reverseposition required for the signal.

Fig. 1 of the second form of apparatus embodying my invention shows aslow pickup relay t controlled by a front contact of track relay T andshows a pickup circuit for relay T controlled by a back contact of relay5*, and a stick circuit for relay T controlled by one of its own frontcontacts. Relays t and T are shown controlled similarly to relays t andT respectively. A slow pickup relay, designated by the referencecharacter t with a corresponding exponent, is similarly controlled byeach of the other detector track relays T, and is therefore not shown inFig. 1 Each of the other track relays T is controlled by its associatedslow pickup relay t similarly to the manner shown for relays T and T andis therefore not shown in Fig. 1

In Fig. 3 the circuits of Fig. 3 are shown divided into two parts, andare modified to include contacts and the control windings of route stickrelays which are designated by the reference character W withdistinguishing exponents. One route stick relay W is associated with thelever for each route end, and two route stick relays W are associatedwith the lever for each of the intermediate points G and ii.

In Fig. 6 the relay V is shown con-trolled by relays t and t in additionto the other relays bywhich it is controlled in Fig. 6. The other routelocking relays V are similarly controlled by other relays t, and aretherefore not shown in Fig. 6

In Fig. 7 a portion of the circuits shown in Fig. 7 for relay m is shownmodified to include a contact of relay t*. The other polarized switchcontrol relays m are to be similarly controlled by the relays t, whichare associated with the track relays for the detector track sections inwhich the switches are located, and are therefore not shown in Fig. 7

Fig. 9 shows the signal control network circuits of Fig. 9 modified onaccount of relays W.

In Fig. 2 of the third form of apparatus embodying my invention, a groupof three push button circuit controllers is provided instead of eachlever K which is shown for a route end in Fig. 2. Each of these pushbutton circuit controllers is designated by the reference character k:with an exponent which includes the letter L meaning left. or the letterR meaning right, or the letter N meaning normal. Instead of each of theintermediate levers K and K of Fig. 2, only one 1 1118. 1 button k isshown in Fig. 2

Fo arr n in the t ck swi hes of ea h route in the positions required fortheroute and for clearing the eastbound signal for the route, theoperator will depress the two push buttons for the route, which have theletter R in their exponents, and will depress the intermediate pushbutton K or Ki for the route. Similarly, for arranging the switches ofeach route and for clearing the westbound signal for the route, theoperator will depress the two push buttons for the route, having theletter L in their exponents, and will also depress an intermediate pushbutton k for the route. 7

Two indicators 6 are shown on the operating board in Fig. '2 adjacenteach group of three push buttons 70, and also adjacent each intermediatepush button Ic. Each of these indicators is given an exponent with theletter L or the letter R. When any route is arranged for an eastboundtraffic movement, the indicators e having an exponent R for the routewill 'be energized. When any route is arranged for a westbound trafiicmovement, the indicators 6 having an exponent L for the route will beenergized.

Fig. 3 shows route stick relays W similar to those which are shown inFig. 3 but also shows a route releasing stick relay designated by thereference character Y with a distinguishing exponent for each route end.

Each of the push button circuit controller contacts by which theserelays are shown controlled is biased to the normally open or thenormally closed position in which it is shown in the drawings. This maybe done by any suitable means, such for example as a coiled spring 28%!shown for contact 234- in Fig. 4.,

Fig. 4B shows circuitsfor call-on control relays Z and Z 1 includingstick circuits controlled by the corresponding relays Y.

Fig. 5 shows the circuits for indicators e of Fig. 2 controlled byrelays W and Y.

In Fig. 9 the circuits of Fig. 9 are controlled by relays W and Yinstead of by levers K as in Fig. .9. v

Having described, in general, the arrangement and operation of variousforms of apparatus embodying my invention, I will now trace in detailthe operation of these forms of apparatus.

As shown in the drawings, all parts are in the normal condition. thatis, each track relay T is energized; .each lever K of Fig. 2 is in thenormal position 11; each push button is of Fig. 2 and each of thecall-on push buttons U and U of Figs. 2 and. 2 is in its normal positionin which it is shown in the drawings; the polar contacts of each switchrelay m are in their normal positions; each switch H is in its normalposition in which it is shown in the drawings; the circuit controller yfor each switch H is in its normal position; each signal S is indicatingstop; relays N, R, X, Z, m, W and Y are deenergized; and indicators eare deenergized.

I will first trace the operation of the first form of apparatus, shownin Figs. 1 to 9, inclusive.

With the polar contacts of relay m in their normal position, and withcircuit controller 11 in its normal position, current is supplied in thenormal direction to relay k by a circuit passing from terminal a: of asuitable source of current, not shown in the drawings, through contact Hclosed in its normal position, contact l3 l8 of circuit controller 11winding of relay M, and contact Ill-49 of circuit controller 11 toterminal 0 of the same source of current. Relay h is therefore energizedin the normal direction, and hence its contacts are in 'the normalposition. Relay h is similarly energized.

On account of switches H and H being in their normal positions, and onaccount of the polar contacts of switch control relay m being in thenormal position, polarized indication relay h is energizedin the normaldirection by a circuit passing from terminal x, through contact 2Ishownto the left, contact 22 22 of circuit controller contact NI -23 ofcircuit controller 11 winding of relay h contact 2l--2 l of circuitcontroller '1 and contract 255-45 of circuit controller y to terminal 0.Relay 71. is similarly energized.

With signals S indicating stop, approach locks ing relay P is energizedby a pick-up circuit passing from terminal ac, through contacts 29, 30and 3| of signals S S and S respectively, contact 32 of relay T and thewinding of relay P to terminal 0. A stick circuit is also closed forrelay P and differs from the pick-up circuit, just traced, only, byincluding contact 3'5 of relay P instead of contact 32 of relay TApproach locking relay P is energized by circuits which are similar tothose just traced for relay P With signal S indicating stop, sticklocking relay Q is energized by its stick circuit passing from terminalthrough contact 36 of signal S contact 38 of relay Q and the winding ofrelay Q to terminal 0. Stick locking relays Q Q and Q are energized bycircuits which are similar to the circuit just traced for relay Q Withall approach and stick locking relays P and Q, respectively, energized,and with all track relays T energized, all of the route locking relays Vare energized as shown in Fig. 6. For example, relay V is energized byits pickup circuit passing from terminal :12, through contacts 43 Mcontact 55 in multiple with contact 46 contact A? in multiple withcontact 48, contacts 49 and 59', and the winding of relay V to terminal0. A stick circuit is also closedfor relay V which includes the pickupcircuit just traced as far as contacts 45 and 46 and thence passesthrough contact 5| of relay V and the winding of relay V to terminal o.

Each of the signal stick relays L and L shown in Fig. 8, is energized,both a pickup and a stickcircuit for each of these relays being closed.The circuits for relay L are closed because certain track relays areenergized, and because switches H and H are in their normal position.The pickup circuit for relay L passes from terminals, through contacts M15', 161, 19', iiil and thewinding of relay L to terminal 0. The stickcircuit which is closed for relay L is the same as the pick-up circuitjust traced, except that it includes contact 8| of relay L instead ofcontact BB The pick-up and stick circuits for relay L are similar,respectively, to those just traced for relay L and will therefore bereadily understood by reference to the drawings.

I will assume that the leverman desires to arrange for an east-boundtraffic movement over route 1, from A to E. He will therefore place thelevers K K and K in their 1" positions, thereby completing a circuit forenergizing relays X X and X passing from terminal in, through contact 89winding of relay X contacts 90 and 93 winding of relay X contact 94winding of relay 2?, and contacts 95 and "33 to terminal 0.

With relay X energized, a circuit will be completed for energizingindicator e passing from terminal :c, through contacts ll l H5 9 andIZII and indicator e to terminal 0. With relays X and X energized,indicators 6X3 and 6 will be energized by circuits which are similar tothe circuits just traced for indicator 6X2, and which can therefore bereadily traced on the drawings.

Relay X upon becoming energized, also completes a circuit for energizingpolarized relay m in the normal direction, passing from the positiveterminal of a source of current which may be a battery 21 throughconductors I31 and I31, contacts Ite IM lfilt MQ I50 IEI I52, I53,winding of relay m and conductor I69 back to battery b With relays X andX energized, relays m and m will be energized in the normal direction bycircuits which are similar to the circuit just traced for relay m andwhich can, therefore, be readily traced on the drawings.

With levers K K and K in their 1 positions, and with relays X X and Xenergized, a circuit is completed for clearing signal S passing fromterminal :10, through contacts I'IE II'I l'lll I82, [33 front point ofcontact I84 contacts I35 I8t I8l 38 I89, 200*, 2lll 292- back points ofcontacts 2E3 and 2M contact 265 back point of contact 266 contact 20'!of signal 8 and the mechanism of signal S -to terminal 0.

When the arm of signal S leaves its stop position, both the pickup andstick circuits previously traced for relay P are opened at contact SI ofsignal With relay P thus deenergized, the pickup circuit previouslytraced for relay L shown in Fig. 8, is open at contact 86 but the stickcircuit for relay L continues closed, and hence relay L continuesenergized.

Upon the deenergization of relay P contact AE opens one path of thecircuits for relay V shown in Fig. 6, but relay V continues energized bya second path through contact 36 Relay P upon becoming deenergized,opens at its contact 55P the pickup and stick circuits for relay Vcausing relay V to become deenergized. With relay V deenergized, thecircuits for relays m and m are open at contacts I58 and I65respectively, thus making it impossible to supply current to thesecircuits which might cause relays m and m to become energized in thereverse direction. The circuit for relay m is also now open at contactIEBI on account of relay P being deenergized.

With relay P deenergized, contact 222 shown adjacent contact ZliI of thecircuit previously traced in Fig. 9 for signal S is open. Contact 222controls opposing signals S S and S An eastbound train approachingsignal S after the route from A to E has been arranged as described,deenergizes approach track relay T which then opens its contact 32 inthe pickup circuit traced for relay P which, however, is already open atcontact 3! of signal S.

When the train passes signal S entering section A-zi, relay T becomesdeenergized. Relay T upon becoming deenergized, opens its contact IZIJin the circuit previously traced for indicator 6X2, thereby causing thisindicator to become deenergized.

With relay T deenergized, its contact I52 is open in the circuit tracedfor relaym which, however, is already open because contact ISI is open.

Contact 59 in one of the pickup circuits for relay V is also open. RelayV is, how-ever, already deenergized because contact 55 is open.

With relay T deenergized, contact HJ opens the stick circuit for relay LRelay L being thus deenergized, will open its contact 205 in the circuittraced for signal S and hence the arm of this signal will return to thestop position.

The arm of signal S upon again reaching its stop position, completes asecond pickup circuit for relay P passing from terminal .12, throughcontacts 29, 30, and .3! of signals 8 S and S respectively, contact 33of relay T and the winding of relay P to terminal 0.

Although relay P now closes its front contacts in the circuits forrelays L V and m these relays are still deenergized because theircircuits are open at contacts of relay T When the train moves out ofsection a-A, relay T becomes energized, completing again the pickupcircuit first traced for relay P through contact 32 of relay T When thetrain enters section ii-ia, relay T will become deenergized, and henceits contact I29 will open and cause indicator e to become .deenergized.As long as the train is in section ii-jy, relay T will remaindeenergized, and, hence its contacts 15 (H and ISI will prevent relays LW and m respectively, from becoming energized.

When the train moves out of section A-zi, relay T will again becomeenergized, causing indicator 6X2 to again become energized by itscircuit previously traced.

When the, train enters section 7'7E, relay T will become deenergized,and hence indicator e will become deenergized on account of its circuitbeing opened at contact l32 When the train leaves section iz-77,permitting relay T to again become energized, indicator e will againbecome energized on account, of the closing of contact I29. Relay T uponbecoming energized, permits relay V to again become energized by itspickup circuit passing from terminal through contact 55 contact l' inmultiple with contact 58 contacts 59' yand 61, and the winding of relayV to terminal 0.

While the train is in-section jj-E, causing relay T to be deenergized,contact '16 will be open and will thus prevent relay L from becomingenergized. When the train leaves section yj-E, relay T upon becomingenergized, causes relay L to again become energized by its pickupcircuit previously traced. Relay T upon becoming energized, also closesits contact l32 and hence indicator e will again become energized by itscircuit previously described.

In order to manually restore signal S to its stop position after it hasbeen cleared, the leverm an can return any one of the three levers K Kand K to its normal position, thereby openingione of the contacts ZOIH39 and ITI respectively, in the circuit previously traced for themechanism of s gnals.

If, after the leverman has arrangedpa route such, for example, as theroute from A to E as previously described, a train has entered the routeand it then desired to provide a call-on signal indication to authorizea second train to enter the routewhile'it is still occupied by the firsttrain, the leverman will let the levers K K and K remain in their rpositions, and will 'depres' call-0n push button U thereby causing relayZ to become energized by its pick-up circuit passing from terminal :0,through contact 234 and the winding of relay Z to terminal, 0. Withlever K in its 2' position, relay Z will be retained in its energizedcondition by its stick circuit passing from terminal a:, through contact235 contact 236 of relay Z and the winding of relay Z to terminal 0.With relay Z energized, a circuit is now completed for signal S which isthe same as the circuit previously traced for signal S 'as far ascontact 203 and thence passing through the front point of contact 204contacts 2| l and 2|? of signals S and S" respectively, and themechanism of signal S to terminal 0. The arm of signal S thereupon movesto its call-on position.

Since the circuit just traced for signal S does not include a contact ofstick relay L the arm of signal S will continue to indicate call-onwhile the route is occupied by a train. In order to restore the arm ofsignal 5 to its stop position, the leverman will return lever K to its nposition, thereby opening contact 235 K1 in the stick circuit for relayZ and thus causing relay Z to become deenergized. r

I will now assume that, with all parts of the apparatus again in theirnormal condition as previously described, the leverman again arrangesthe switches of route 1 and clears signal S, by placing levers K K and Kin their 1' positions. If now before an eastbound train enters sectionw-A, the leverman should desire to arrange for a traflic movement oversome other route beginning at point A such, for example, as route 2 fromA to F, he will place lever K at its 1' position, and will permit leversK and K to remain in their r positions.

However, as long as lever K remains in its 1* position, the circuitpreviously traced through contacts 89, 9 1i and I03 will remain closed,and hence relay X4 will remain energized. As long as relay X4 isenergized, the route circuit controlled by contact 9| will remain openat contact 92 With levers K K and K in their r positions, and withrelays X X and X energized, the circuit for the mechanism of signal Swill remain closed, and hence signal S will continue to indicateproceed. V

The leverman must therefore return lever K to its n position, therebydeenergizing relay X and so causing a circuit to be completed forenergizing relays X X and R in series, passing from terminal .r, throughcontact SI winding of relay R contacts 92 and 93 winding of relay Xcontact 9 1 winding of relay X and contacts 95 and I83 to terminal 0,With relays X and X thus energized, indicators e and e will again becomeenergized *as'previously described.

With relay R energized, contact I35 will be closed in the circuit forenergizing indicator c which, however, will be open'at contact I36 untilswitch H responds to the 'energization of relay R The energization ofrelay R cau'ses a circuit to be completed for energizing relay m in thereverse directiompassing from the positive terminal of battery-b throughconductor I69, winding'of relay m contacts l 68', IG I IBB ISE backpoint of contact "51 and contact IIE back tobattery b With relay menergized in the reverse-direction, switch mechanism M will be suppliedwith current for moving switch H to its reverse position, such currentpassing from battery b through contact closed in the reverse position,mechanism M and contact I5 closed in the reverse position back tobattery b Upon the reversal of the polar contacts of relay m terminal atis disconnected from indication relay h and a shunt circuit is completedfor relay 12*, passing from contact 20 closed in the reverse position,through contact I8 --I8 of circuit controller 1 the winding of relay 11.and contact I9----I9 of circuit controller back to contact 20 During themovement of switch H from its normal to its reverse position, indicationrelay h is shunted by a second circuit including contacts I8-I8 andI9-I9 of circuit controller 11*. Upon the completion of the operationoflswitch H to its reverse position, relay 11 becomes energized in thereverse direction by a circuit passing from terminal :2, through contactIl closed in the reverse position, contact IS -I9 of circuit controllerg winding of relay 7%, and contact I8IB of circuit controller 1 toterminal 0. Upon the energization of relay in in the reverse direction,contact I34 will close the circuit for indicator e and hence thisindicator will now become energized.

Relay it, upon becoming energized in the reverse direction, alsocompletes a circuit for operating the mechanism of signal S passing fromterminal at, through contacts lI9 I88 and I8I contact I82 in theright-hand position, contact I83, front point of contact 34 contactsI85, I86, I81, I88 IBQ 200 contact ZBI in the right-hand position,contact 292 back points of contacts 203 and 2M contact 205 front pointof contact 206 contact 208 contact 209 of signal S and the mechanism ofsignal S to terminal 0.

I will. now assume that the leverman desires to again arrange route 1for a traflic movement from A to E. He will therefore return lever K toits n position, but will permit levers K and K to remain in their 7*positions, and will place lever K in its r position, thereby againcompleting the circuit previously traced for energizing relays X X and Xin series. With relays X. and X energized, indicators e and. a will beenergized as previously described. With relay X energized, contact I36will be closed in the circuit for indicator e but this circuit will nowbe open at contact I 34 until switch H responds to the energization ofrelay X by returning to its normal position.

On account of relay X being energized, relay m is now again energized inthe normal direction. With relay m energized in the normal direction, acircuit will be completed for mechanism M passing from the positiveterminal of battery b through contact I5 in its left-hand position,mechanism M and contact I I in its left-hand position back to battery hMechanism M will, therefore, now return switch H to its normal position,after which signal S will be cleared by its circuit previously traced.

I will next assume that while route 1 is arranged for a trafiic movementfrom A to E, and while signal S is indicating proceed, the operator, bymistake, attempts to arrange for a traffic movement over route 8 from Bto F. He will, therefore, place levers K K and K in their 1' positionsfor energizing relays X X, R and R in series. With relays X and Xenergized for arranging route 1 from A to E, the circuit for arrangingroute 8 will be open at contacts 96 and 92 and hence none of the relaysX X R and R can be energized. With levers K K and K still in their rpositions, and with relays X X and X still energized, the circuit forsignal S will still be closed and this signal will continue to indicateproceed.

From the two examples of operation which I have just given, it followsthat, after the apparatus has been put into condition for arranging agiven route, the leverman cannot by mistake put the signal for the givenroute to stop, nor arrange the switches of a conflicting route while thecontrol apparatus is still in condition for arranging the given route,although no mechanical interlocking is provided for control levers K.

I will assume that all parts of the apparatus have again been returnedto their normal condition, and that the operator has again arrangedroute 1 for a trainc movement from A to E and cleared signal S If, now,after an east-bound train enters section a-A, deenergizing relay T theoperator should desire to send this train over some other route thanroute 1, such, for example, as route 3 from A to D, he can return leverK to its normal position, thereby opening the circuit for relays X X andX at contact 89 With lever K returned to its normal position, contact HPwill be open in the circuit for signal S and hence the arm of signal Swill return to the stop position.

On account of relay T being deenergized by the train in section a-A,relay P will not pick up when the arm of signal S is returned to itsstop position. In order to energize relay P the leverman will start theoperation of time release J Contact ne in the circuit for signal S shownin Fig. 9, will immediately open and, after the lapse of a measuredperiod of time, contact 34 of release J will close, causing relay P tobecome energized by a third pickup circuit, passing from terminal at,through contacts 29, 30 and 3| of signals S S and S respectively,contact 34 of release J and the winding of relay P to terminal 0. I

With relay P energized, relay V will become energized by its pickupcircuit previously traced, and hence the leverman can now proceed toarrange any other route originating at point A, but neither signal S norS can be operated to the proceed position for governing movements oversuch a route until the leverman restores the contacts of release J totheir normal position.

In order to send the train over route 3 from A to D, the operator willplace levers K and K in their 7" positions, and will also place lever Kin its r position if it is not already in that position. A circuit willthereby be completed for energizing relays R and X, passing fromterminal ax, through contacts 96 and 99 winding of relay X contact IIJQwinding of relay R contacts IIJI and 182*, and contact I03 in itsrighthand position to terminal 0.

With relay R energized, switches H and H will be operated to' theirreverse positions, and signal S will then be cleared by its circuitpassing from terminal :13, through contacts HI I92 I93 I9 l IQEE I 91I98 in its righthand position, I99 2%, 2m 202 front point of contact2&3, contact 2I0 contacts 2H and 252 of signals S and 8 respectively,and the mechanism of signal S to terminal 0.

I will next assume that the operator has again returned the apparatus tothe normal condition, and that he then desires to send a train by therun-around path from A to E over switches H H H and H reversed. He willtherefore place levers K K and K in their right reverse positions 1,thereby completing a circuit passing from terminal 1:, through contact89 winding of relay X contacts 96 9?, 91 winding of relay R contact IMF,the winding of relay R contacts Illl and 32 and contact I03 in therighthand position to terminal 0.

- With relays R and R energized, switches H H H and H will be operatedto their reverse positions. With these switches in their reversepositions, a circuit will be completed for the mechanism of signal Spassing from terminal at, through contacts I'IG I Ti I18 I82), I83, backpoint of contact 36 contacts I90 I94, I95, IQlS and IN, contact I 98 inits righthand position, contacts I959, 200*, 20I in its right-handposition, contact 202 front point of contact 203 contact 2| contacts 2and 2I2 of signals S and 8 respectively, and the mechanism of signal Sto terminal 0.

I will assume that the apparatus has again been returned to its normalcondition, and that the leverman desires to send a train over route 1 inthe westbound direction from E to A. He will therefore place levers K Kand K in their left reverse positions f, causing a circuit to becompleted for energizing relays X X and X in series, passing fromterminal 1:, through contacts I03 and 95 winding of relay X contact 94,winding of relay X contacts 93 and 90 winding of relay X and contact 89in its left-hand position to terminal 0. With levers K K and K in theirleft reverse positions and with relays X X and X energized, a circuitwill be completed for the mechanism of signal S passing from terminal1', through contacts 222 and 2DI front point of contact ZBEI contactsI89, I88, I81, I85, I 35, front point of contact I84 contacts I83, I82,and H8 contact I11 in its left reverse position, and the mechanism ofsignal S to terminal 0.

I will now trace the operation of the second form of apparatus shown inthe drawings com- I prising Figs. 1 2, 3 4, 5, 6 7 8 and 9 As shown inthe drawings, all parts of the second form of apparatus embodying myinvention are in the normal condition. I will now assume that with allparts thus in the normal condition, the operator desires to arrange fora traffic movement over route 1 from A to He will therefore place leversK K and K in their r positions. With levers K circuit will be completedfor energizing relays W and X in series, passing from terminal at,through the winding of relay W contacts 249, and ZEI winding of relay Xcontact 95, contact Ill3 in its right-hand position, and contact 241 toterminal 0. Relay W upon becoming energized by the circuit just traced,closes its contact 248 in multiple with contact 249.

With lever K in its 1' position, and with relay W energized, a circuitwill be completed for energizing relays W X and X in series, passingfrom terminal 1:, through the winding of relay W contact 89 in itsright-hand position, winding of relay X contacts 96 and 93 winding ofrelay X and front point of contact 25I of relay WiliR to terminal 0.Relay W upon becoming energized, closes its own contact 246 in multiplewith contact 89.

With relays W W X X and X energized,

and K in their r positions, a,

their 1 positions, a circuit a circuit will be completed for themechanism of signal S passing from terminal ac, through contacts Il6 253I18 I 82 I83 front point of contact I84 contacts I85, I86, I8'I I88, 252front point of contact 200, back point of contact 253, contacts 254 202back points. of contacts 2413 and 204 contact 2D5 back point of contact206 contact 20'! of signal S and the mechanism of signal S to terminal0.

I will now assume that with the switches H H and H arranged for atrafiic movement over route 1 from A to E, and with signal S indicatingproceed, the leverman, by mistake, attempts to arrange for a trafficmovement over route 2 from A to F by placing lever K in its 7 position-On account of relay X being energized by the circuit previously traced,the circuit for relays W and R will be open at contact 92 and hence theplacing of lever K in its r position will have no effect on switch H noron either of the other switches of route 1.

If the operator should, by mistake, change the position of lever K whileattempting to arrange some other route while signal :3 is indicatingproceed for a trafiic movement over route 1 from A to E, such anoperation of lever K will have no effect since relay W is now energizedby its stick circuit. Also, any change in the position of lever K wouldhave no efiect on relay W since this relay is now energized by its stickcircuit.

If, however, the operator should change the position of lever K he wouldthereby open contact I03 in its right-hand position, causing relays Wand X to become deenergized. Relay W l, upon becoming deenergized, dropsits contact 25I, thereby breaking the circuit previously traced forrelays W X and X and causing these relays to also become deenergized.

It follows that, after the operator has once placed levers K K and K intheir r positions for arranging the switches of route 1 and for clearingsignal S this route cannot be disturbed except by a change in theposition of lever K Similarly, if the switches of any other route arearranged in the position required for that other route, and if thesignal for the route has been cleared, no change can be made in thepositions of theswitches, nor can the signal be changed by any otherlever K than the lever for the route end at which the signal is located.

I will next assume that all parts of the apparatus are again in theirnormal condition, and that the operator then desires to arrange for atrafiic movement inthe opposite direction over route 1- from E to A.

He will therefore place levers K K and K in their f positions.

With levers K and K in will be completed for energizing relays W X and Xin series, passing from terminal :12, through the winding of relay lNcontact ZSfi contact 25I of relay W winding of relay X contacts 93 andwinding of relay X contact 89 in the left-hand position, and contact 2'l7 to terminal 0. Relay W upon becoming energized, closes its contact243 in multiple with contact 258 With lever K in its f position, andwith relay W now energized, a circuit will be completed for energizingrelays W and X in series, passing from terminal as, through the windingof relay W contact IEJ3 in its left-hand position, contact 95 of relay Xand the front point of 25W, to terminal 0. I Relay W winding contactupon becoih g i energized.

With relays W W X X and X thus energized, a circuit will be completedfor the mechanism 'of signal S passing from terminal .27, through.contacts 222 253 frontpoint of contact 288 contacts 252 [88 llll I86, I,front point of contact I34 contacts [83, [82 H8 back point of contact253 conredraw, and the mechanism of signal S to* terminal 0. r

If now a westbound train enters section y'j-E, relay T will becomedeenergized, causing relay t shown in Fig. 1 to also become deenergized.If, due'to rust on the rails or to some other cause, there should be amomentary lossof shunt, permitting relay T to become energized by itspickup circuit which includes contact 2 12 of relay t*, a circuitcontrolled by contact Z ll of relay T for energizing relay t wouldbecome closed.- Relay 1& is, however of the type having a slow pick-up,and therefore a brief period of time will elapse before relay i willclose its front contacts. During this intervaLthe momentary loss ofshunt will have passed, and relay T will'again be de- By observing thecircuits shown in Figs. 6 and 7 it will be noted that during the timethat relay-T has been-energized-on account of the momentary loss ofshunt, the pick-up circuit for .relay V is held open on account ofcontact 243 being open, and the circuit for relay m is held openonaccount of contact 245 being open. Relay t therefore preventsfalserelease of relays V and m in the event of a momentary loss of shuntwhich permits relay T to become energized for a brief period of time."When the train leaves section ii-E, relay T becomes energizedby itspick-up circuit which. includes contact M2 of relay t 4 becomingenergized, closes its own contact 24s in multiple withcontact 2&2 ofrelay t I will next trace the operation of the third form of apparatuscomprising the parts shown in Figs. 1, 2 3 ,4 5 6, 7, s and 9 As shownin thedrawings, all parts of the third form ofapparatus embodying myinvention are in the normal condition. I will now assume that withan"parts thus in the normal condition, the, operator desires to arrangefor a tramcmovement over route 1 from A to E. He will therefore dopresspush buttons k lc and 'k Push button upon being depressed, completes acircuit'for energizing relay' Y passing from terminal a:,,. throughcontacts 255 and256 and the winding of relay Y to terminal 0. Relay Yupon becoming energized, completes its stick circuit passing fromterminal as, through contacts 25'! and 259 contact 265 of relay Y andthe winding of relay Y to terminal'o.

Push button k upon being depressed, closes its contact 26!, and hence,with relay Y energized, a circuit will be completed for energizingrelays W and X in series, passing from termi nal (17, through contact250 winding of relay W contact m3 of' relay W winding of relay X contact95, and contact 264 of relay Y to terminal 0. Relay W t, upon becomingenergized, closes its contact 282 in multiple with Push button 7cupon'being depressed, closes its contact 265 and hence, with relay'WRelay T upon energized, closes its contact 246 in multiple with contactH13 "W to terminal 0.

energized, closes its contact 236 in multiple with winding of relay Wcontact 261 of relay Y winding of relay X contacts 90 and 93 winding ofrelay X and contact 268 of relay Relay W upon becoming contact 265 Withrelay Y energized, indicator c is energized by its circuit passing fromterminal :0, through contact slit, and indicator e to terminal 0. Withrelay W energized, indicator c is likewise energized by its circuitwhich includes contact 275 With relay W energized,

indicator e will be energized by its circuit which includes contact 272With indicators. e e' and e energized, the operator can see at a glancethat the control apparatus is in condition for arranging the switches ofroute 1 and for clearing signal El Indicators e, shown in Fig. 5therefore serve the purpose of informing the operator as to thecondition of the apparatus directly controlled by push buttons it. Suchindicators'are not needed for the apparatus of the first two forms shownin the accompanying drawings since levers K are not biased to any givenposition, and hence the positions of the levers will indicate to theoperator the condition of the control apparatus.

After the switches H H and H have been operated to their normalpositions if they are not already in those positions, the. energizationof relays Y X W X X and W will complete a circuit for the mechanism ofsignal S passing from terminal :0 through contacts H6 2'H5 2'll H8 I82,M3 front point of contact 58 3 contacts H85, H88, H81, I88, ZEB 268front point of contact 2'l'l contacts 219 ZBZ back points'of contacts263 and 204 the pickup circuit for relay W is open at contact 263 ofrelay W and hence the operator cannot energize relay W by depressingpush button Any operation of push button Ic will therefore not causerelay W to be deenergized.

If, however, the operator should depress push button 7c he Will open thestick circuit for relay Y at contact 259 Such deenergization of relay Ywill cause its contact 264 to open the circuit for relays X and W RelayW being thus deenergized, will open at its contact 268, the circuit forrelays W X and X causing these relays to also become deenergized. Sinceeach of the other routes is similarly controlled, it follows that afterthe switches of any route have been arranged in the positions requiredfor the route and a signal has been cleared for governing traiiicmovements over the route, the

operator can make no change in the route except by depressing the normalpush button for the route end at which the signal is located.

A train, upon entering any of the routes in response to the clearing ofa signal for the same route, will also open the stick circuit for therelay Y for the route, thereby causing the route stick relays and theswitch control relays to be 'deenergized similarly to the mannerdescribed when the oper'atordepresses the normal push butbuttons k glcand 70 ton for the route end at which the signal is located. If, forexample, route 1 has been arranged upon passing signal S, wil deenergizerelay T which will thereupon open its contact 257 in the stick circuitfor relay Y which, upon becoming deenergized, causes relays X W X X andW to become deenergized.

I will now assume that while the train is still occupying route 1, theoperator desires a second train to follow the first train into route 1.He will therefore depress push buttons k and U contemporaneously. Pushbutton k upon being depressed, will close the pickup circuit previouslytraced for relay Y and push button U upon being depressed, will close apickup circuit for relay Z including contact 234 With relay Z energized,a second stick circuit will be completed for relay Y which is the sameas the stick circuit previously traced except that it includes contact258 instead of contact 251'.

With relay Y energized, a stick circuit is completed for relay Z passingfrom terminal at, through contact 21!, contact 236 of relay Z andthewinding of realy Z to terminal 0. Re-

lays Y and Z will therefore continue energized by their stick circuitsafter push buttons k and U have returned to their normal positions. The

operator will now depress push buttons K and K which, with relay Yenergized, will cause relays W W X X and X to again become energized.

With these relays and relay Z energized, a circuit is completed forcausing signal S to display the call-on indication. This circuit is thesame as the circuit previously traced for signal S as far as the backpoint of contact 203 and thence passes through the front point ofcontact ZM contacts 2 and N2 of signals S and 8 respectively, and themechanism of signal S to terminal 0. a With the apparatus thus arrangedfor causing the call-011 indication to be displayed by signal S", relayY cannot be deenergized by a train, and can only be deenergized by theoperator depressing push. button k and thereby opening contact 259 inthe stick circuit for relay Y I will next assume that the apparatus hasbeen returned to the normal condition and that the operator then desiresto send a train over route 5'from F to A. He will therefore depress pushPush button 7e upon being depressed, completes, at its contact 255 apickup circuitfor relay Y passing from terminal at, through contacts 255and 258 and the winding of relay Y to terminal 0. Relay Y upon becomingenergized, completes its stick circuit passing from terminal .73,through contacts 2'10 and 259 contact 263 of relay Y and the winding ofrelay Y to terminal 0.

With relay Y energized, and with push button k depressed, a circuit willbe completed for energizing relays W R and R in series, passing fromterminal cc, through contact 269 winding of relay W contact 263 of relayW winding of relay R contacts 97 96 and'92 winding of relay R andcontact 264 of relay Y to terminal 0, Relay W upon becoming energized,closes its contact 262 in multiple with contact 269 With relay. WGenergized, and with push button k depressed, a circuit will be completedfor energizing relays W and R in series, passing from terminal .1,through contact 265 windingfof relay W contact 26'! of relayY contactstheir right reverse positions.

IUZ and HH winding of relay R and con tact 268 of relay W to terminal 0.Relay W upon becoming energized, closes its contact 266 in multiple withcontact 265*.

With relays W R W R R and Y energized, a circuit will be completed forthe mechanism of signal S when the switches have been arranged tocorrespond with the energized condition of the relays X and R; thiscircuit passing from terminal a, through contacts 222 216, 277, backpoint of contact 200 contacts I99 198 lsl 218 I95 let in its right-handposition,'|99 I8 l l83 I82 in its righthand position "N front point ofcontact 211, contact 279 and the mechanism of signal S to terminal 0. 1

I have described, for a few typical trafiic movements the operation ofeach of three forms of apparatus embodying my invention. From thosedescriptions of operation, and from the preceding general description,operation of each of the three forms of apparatus for every otherpossible traffic movement will be readily understood by reference to thedrawings.

Apparatus of each of the three forms embodying my invention is shown fora layout including switches which can be arranged for eleven differentroutes. Traffic movements can be made in either direction over each ofthese routes.

In each of the first two forms of apparatus shown in the accompanyingdrawings, a manually operable control lever is provided for each routeend or signal location. Control levers are also provided for pointsintermediate the opposing signals in order to control run-around moves.Each route for which an intermediate lever is provided may be consideredas being divided into two sub-routes each of which extends from theintermediate point, for which the intermediate lever is provided, to theend of the rotue at which a signal is located. Each control lever hasthree positions, comprising a normal or middle position, a reverseposition to the right for arranging the switches and clearing theeastbound signal for the route, and a reverse position to the left forarranging the switches of the route and for clearing the westboundsignal for the route. In order to arrange the switches of each route inthe positions required for the route, and in order to clear theeastbound signal for the route, the operator will place all the leversfor the route in Similarly, in order to. arrange the switches of eachroute in the positions required for the route, and in order to clear thewestbound signal for the route, the'operator will place all theleversfortheroute in their left reverse positions.

In the first two forms of apparatus, a normal anda reverse indicator isprovided for each switch. The normal indicator for each switch is enerized only when a normal control relay for the switch is energized whilethe switch is in its normal position, and while the detector tracksection relay for the switchis energized. The reverse indicator for eachswitch is similarly energized only when a reverse control relay for theswitch is energized while the switch is in its reverse position, andwhile a detector track relay for the switch is energized. r

In Fig. 1 of the second form of apparatus, an arrangement is shown forprotecting against false release of the switches in theevent of amomentary loss of-shunt in a detector track circuit for a switch.

In the thirdform of apparatus shown in-the i accompanying drawings, agroup of three push button circuit controllers is shown for each routeend, one of which is designated left, a second of which is designatedright, and the third of which is designated a normal push button, Onepush button is also shown for each of given inter-- mediate points ofthe routes.

In order to arrange the switches of any given route in the positionsrequired for the route, and in order to clear the eastbound signal forthe route by the third form of apparatus, the operator will depress thetwo right push buttons and the intermediate push button for the route.Similarly, in order to arrange the'switchesior any given route in thepositions required for the route, and in order to clear .the westboundsignal for the route, the operator will depress the two left pushbuttons and the intermediate push button for the route.

Each of thethreeiorms of apparatus is so adapted that whenthe apparatusis in condition for arranging the switches of any given route,- and forclearing one of the signals for the route, a mistaken operation of thecontrol levers or push buttons for a conflicting route will have noefiect on the condition of theswitches or of the signal for the givenroute.

In the first formof apparatus, a signal, when indicating proceed for anygiven route, will be placed at stop and permit a conflicting route to bearranged if any of the levers for the given route is moved to adifferent position; If, for example, signal S is indicating proceed, theoperator can cause this signal to display the stop indication bychanging the position of lever K and thereby openingcontact Hi in thecircuit for the mechanism of signal S ,or by changing the position oflever K and thereby opening contact M9 in the circuit for signal S 20!by changing the position of lever K and thereby opening contact [11 inthe circuit for signal S.

The second and third forms of apparatus are so adapted that when theapparatus is in condition for arranging the switches of any given routeand clearing one of the signals for the route, the signal can be put tostop, manually, and the route can be changed only upon opera tion' ofthe lever or the normal push button for theroute end at which the signalis located. The third form of apparatus is also adapted for the'routestick relays for each route to be automatically deenergized when a trainenters the route.

In the second form of apparatus, if, for example, route 1 has beenarranged and signal S is indicating proceed, the route control apparatusshown in Fig. 3 can be restored to its normal condition only by changingthe position of lever K and thereby opening contact 103 in the circuitfor relays X and W At the same time, the operator causes signal S toin-. dicate stop by changing the position of lever K and thereby openingcontact 254*.

In the third form of apparatus, if, for example, signal S is clearedwhile the switches of route 1 are arranged in the positions required forthe route, the apparatus of Fig. 3 can be restored to its normalcondition only by a train deenergizing relay T and thereby openingcontact 25'!" in the stick circuit for relay Y or by the operatoropening contact 259? inthe stick circuit for relay Y Thedeenergizationof relay X, by .opcningcontact -2112 ataits front point,-will cause thearm of signal S to'indicate In the third form of apparatus, having pushbutton circuit controllers biased to a normal position, indicators areprovided to show the condition of the control apparatus. Theseindicators not only show the route for which the control apparatus hasbeen arranged, but also show the direction of trafiic movements forwhich the route has been arranged.

Although I have herein shown and described only three forms ofinterlocking control apparatus embodying my invention, it is understoodthat-various changes and modifications maybe made therein within thescope of the appended claims without departing from the spirit and scopeof my invention.

Having thus described my invention, what I claim is:

1. In an interlocking control system for a plurality of railway tracksinterconnected by switches to form a plurality of routes, 2. normal anda reverse control relay for each of said switches, a plurality ofinterconnected circuits for said plurality of routes each of saidcircuits including in series the control element of the normal. or thereverse control relay for each switch in a corresponding route and alsoincluding manually controlled means and a source of current foroperating the relays in the circuit, and means controlled by the normaland reverse control relays for each switch for operating the"correspondingswi'tch to normal and reverse positions respectively.

2. In an interlocking control system for a plurality :of railway tracksinterconnected by switches to form a plurality of routes, a normal and ia reverse control relay for each of said switches, a' plurality ofinterconnected circuits for said plurality of routes each of saidcircuits including the control winding of the normal control relay and aback contact of the reverse control relay or the control winding of thereverse control relay and a back contact of the normal control relay.for. each switch in a corresponding route and supplied with current bymanually controlled means for operating the relays in the circuit, andmeans controlled by the normal and reverse control relays for eachswitch for operating the corresponding switch to normal and reversepositions respectively.

3. In an interlocking control system for a plurality of railway tracksinterconnected by switches to form a plurality of routes, a normal and areverse control relay for each of said switches, a manually controllabledevice for each route end, a circuit network comprising a plurality ofcircuits each of which corresponds to one of said routes and each ofwhich includes in series the control element of the normal or thereverse control relay for each switch in the corresponding route andalso the manually controllable device for each end of the route as wellas a source of current for operating the relays of the circuit, andmeans controlled by the normal and reverse control relays for eachswitch for operating the corresponding switch to normal and reversepositions respectively.

4. In an interlocking control system for a plurality of railway tracksinterconnected by switches to form a plurality of routes, a normal and areverse control relay for each of said switches, a manually controllabledevice for each route end, a circuit network comprising a plurality, ofcircuits. each oi-which corresponds-to

